This invention relates to a new and distinct cultivar of Calibrachoa plant, hereinafter referred to by the name xe2x80x98Kakegawa S8xe2x80x99. xe2x80x98Kakegawa S8xe2x80x99 is a hybrid. In 1996, the inventors Masao Bessho and Tosimi Ohga crossed a variety obtained from a commercial market in South America with a patented hybrid at a commercial nursery in Kakegawa, Japan. The F1 progeny of this cross were found to have desirable characteristics, and the present invention was selected from this generation. The plant has been asexually reproduced through a number of generations since that time and its distinguishing characteristics have remain firmly fixed.
The Calibrachoa genus is a relatively new designation for a number of species that were formerly considered part of the Petunia genus.
The Petunia genus was originally established in 1803 by A. L. Jussieu, who described both P. parviflora Juss. and P. nyctaginiflora Juss. as type species. Using a non-horticultural system that selected the first mentioned species as the type species (lectotype), N. L. Britton and H. A. Brown declared P. parviflora Juss. as the type species for Petunia in 1913.
During the 1980""s and 1990, H. J. Wijsman published a series of articles regarding the ancestry of P. hybrida (Hook.) Vilm., the Garden Petunia, and the inter-relationship of several species classified as Petunia. These studies discovered that P. hybrida (Hook.) Vilm. and its ancestral species, P. nyctaginiflora Juss. (=P. axillaris (Lam.) B.S.P.) and P. violacea Lindley (=P. integrifolia (Hook.) Schinz and Thellung.), possessed 14 pairs of chromosomes while several other species, including P. parviflora Juss., possessed 18 pairs of chromosomes. Since P. parviflora Juss. was the lectotype species for the Petunia genus, Wijsman and J. H. de Jong proposed transferring the 14 chromosome species to the genus Stimoryne. Horticulturists opposed reclassifying the Garden Petunia and in 1986, Wijsman proposed the alternative of making P. nyctaginiflora Juss. the lectotype species for Petunia and transferring the 18 chromosome species to another genus. The I. N. G. Committee adopted this proposal. By 1990 Wijsman had transferred several species, including P. parviflora Juss. (=C. parviflora) to Calibrachoa, originally established by Llave and Lexarza in 1825. Calibrachoa parviflora (=C. mexicana la Lave and Lexarza) is now the type species for the genus Calibrachoa.
Classification of the current Petunia and Calibrachoa species is still in progress. New species are also being identified. At present, Calibrachoa can be distinguished from Petunia based on the higher chromosome number, chromosome morphology, plant branching habit and type of flower bud aestivation.
To summarize a few of the more easily identified distinguishing characteristics: whereas Petunia species have 2n=14 chromosomes, Calibrachoa species have 2n=18 chromosomes. Whereas Petunia species bear a flower peduncle and one new stem from a node, Calibrachoa bear a flower peduncle and up to three stems. Finally, Petunia species have a cochlear corolla bud. A single outermost petal covers the other four petals which are radially folded and terminally contorted. Calibrachoa flower buds are flat with all five petals linearly folded. The two lower petals are fused together and form a cover around the three other petals.
Further information on the transfer of certain species of Petunia to Calibrachoa can found in the following articles which are incorporated by reference herein. H. J. Wijsman, On the Interrelationships of Certain Species of Petunia VI New names for the species of Calibrachoa formerly included into Petunia (Solanaceae), Acta. Bot. Neerl. 39(1), 101-102 (March, 1990). H. J. Wijsman and J. H. de Jong, On the Interrelationships of Certain Species of Petunia IV Hybridization between P. Linearis and P. Calycina and Nomenclatorial Consequences in the Petunia Group, Acta. Bot. Neerl. 34, 337-349 (August, 1985). H. J. Wijsman, J. H. de Jong and T. M. Pedersen, On the Interrelationships of Certain Species of Petunia III The Position of P. Linearis and P. Calycina, Acta. Bot. Neerl. 32(4), 323-332, (August, 1983). Toshio Ando, Yoshiro Ueda, and Goro Hashimoto, Historical Survey and Present Status of Systematics in the Genus Petunia Jussieu (Solanaceae), Technical Bulletin of Faculty of Horticulture, Chiba University, No. 45 (1992).
The new variety""s female parent is a member of the Calibrachoa genus. No species determination of the female parent has been made. The female or seed parent is known to the inventors by its breeder codexe2x80x94C-10A. Parent C-10A was found in a commercial market in South America. It is characterized by white funnel-shaped flowers having a purple ring around the base of the throat and a decumbent growth habit.
The male parent was patented in the United States on May 6, 1997, by the same inventors. Its U.S. patent number is U.S. Plant Pat. No. 9,885. The inventors have named it xe2x80x98Liricashower Bluexe2x80x99. Like the seed parent, its botanical classification has not been carried to the species level. In U.S. Plant Pat. No. 9,885, the genus for xe2x80x98Liricashower Bluexe2x80x99 was identified as Petunia. Since that time, as discussed above, the inventors have learned that the genus Petunia has been split by the I.N.G., and this particular variety, because of its chromosome number and bud aestivation is more accurately characterized as a member of the Calibrachoa genus. xe2x80x98Liricashower Bluexe2x80x99 is itself a hybrid plant, the result of a cross between plants obtained from commercial markets in South America.
The distinguishing characteristics of the parent xe2x80x98Liricashower Bluexe2x80x99 include bright funnel-shaped flowers, a decumbent growth habit and a large profusion of blooms. With regard to the color of the flowers, specifically, the throat and limbs of the petals are violet (R.H.S. 88A at maturity) and the tube is white to light green-yellow.
The initial cross-pollination of the parents, resulting in F1 generation seed, was made in October of 1996. This F1 seed was sown and yielded 20 plants. From these 20 plants, three plants were selected for their appealing flower color and decumbent growth habit. In August of 1997, the three selected plant lines were vegetatively propagated and tested for ease of reproducibility and stability of traits. The present variety was selected from the three for its vigorous growth, decumbent habit and light pink flower color. xe2x80x98Kakegawa S8xe2x80x99 has a pigmentation pattern similar to its pollen parent, xe2x80x98Liricashower Bluexe2x80x99.
In December of 1997, cuttings of xe2x80x98Kakegawa S8xe2x80x99 were sent to a commercial nursery in Salinas, Calif. During the spring and summer of 1998, plants were grown under the direction and supervision of the inventors for evaluation of stability of the line""s desired traits. Plants were grown in hanging pots at the commercial nursery in Salinas, Calif., and in cultivated fields at the commercial nursery in Kakegawa, Japan. Vegetative propagation in Japan was done in Kakegawa, Japan. The terminal 1.0 to 1.5 inches of an actively growing stem is excised. The basal half is stripped of leaves and dipped in a 1:19 dilution of Dip-N-Gro rooting solution (solution:water). The dipped portion of the stem is then inserted into moist peat-based soilless plant growing media. Soil trays with 1.0 inch diameter by 1.5 inch deep cells are used. The cuttings are kept in a warm greenhouse under a clear plastic tent with occasional misting from and automatic system. After about four weeks the cuttings have grown roots, bound together the soil as a root ball and can be transplanted to pots. Two generations of successive propagation (December 1997 and December 1998) were performed between the final selection and collecting data for the application. Vegetative propagation in Salinas, Calif. was performed in greenhouses at the Sakata Seed America Plug and Propagation facility. It takes approximately four weeks to produce a root cutting. xe2x80x98Kakegawa S8xe2x80x99 was determined by the inventors to have its characteristics, as herein described, firmly fixed.
xe2x80x98Kakegawa S8xe2x80x99 is a new variety of Calibrachoa plant having a decumbent and compact growth habit. The plant grows vigorously, branches only moderately, and makes an excellent hanging basket. Its flowers are funnel-shaped. The petals are united and each has a fissure and a slight indent. The flowers are axillary and solitary. Fully-opened flowers have a diameter between 3.1-3.5 cm. The throat and limbs of the petals are light pink (R.H.S. 74C, red-purple group). The tube is alternately white or yellow (R.H.S. 7B, yellow group). The plant is very resistant to rain, heat and drought. The plant grows and flowers best under low soil pH conditions (pH 5-6). Typically, young flowers will close under low light and low temperature conditions such as late in the day and at night, giving them their generally funnelform appearance.
The new variety is distinguished from other Calibrachoa plants by the combination of its characteristics. It combines a unique flower color with large flowers, a decumbent, vigorous growth habit with moderate branching, and a tendency for its flowers to close in the evening.
The closest commercial cultivar of which the inventors are aware is the petunia-like plant named xe2x80x98Million Bells Trailing Pinkxe2x80x99. The distinguishing characteristics which differentiate xe2x80x98Kakegawa S8xe2x80x99 from xe2x80x98Million Bells Trailing Pinkxe2x80x99 are: